The Role of Reduced Surface Sulfur Species in Se(VI) Removal #WorldResearchAwards
Introduction Sulfidized nano zero-valent iron (S-nZVI) has emerged as a highly effective material for the reductive removal of toxic oxyanions from aqueous environments. Its enhanced performance compared to pristine nZVI is attributed to improved electron selectivity and conductivity between the Fe(0) core and target contaminants. Sulfidation modifies the particle surface, introducing reactive sulfur species that fundamentally alter redox behavior . While S-nZVI has been widely studied for contaminant removal, the specific role of these sulfur species has remained insufficiently explored. Understanding their contribution is essential for optimizing S-nZVI design and predicting its behavior in both engineered and natural sulfidic systems. Mechanism of Se(VI) Reduction by S-nZVI The reduction of Se(VI) by S-nZVI occurs at significantly enhanced rates, up to ten times faster than with non-sulfidized nZVI. This acceleration is strongly influenced by the molar S/Fe ratio and selenium co...